1. Field of the Invention
The present invention relates to a data recording and reproducing apparatus and method for recording and reproducing data including audio/visual data (AV data) and the like.
2. Description of the Related Art
In recent years, following multi-channeling for provision of information owing to the spread of CATV (cable television) or the like, a demand for reproducing plural data simultaneously from single data recording and reproducing apparatus, unlike conventional VCRs (video cassette recorder), has become higher. In order to satisfy this demand, a data recording and reproducing apparatus called AV (Audio/Visual) server, which records and reproduces plural audio/visual data using a random accessible recording and reproducing medium such as a semiconductor memory or a hard disk, is spreading.
FIG. 27 is a functional block diagram showing a schematic constitution of a data recording and reproducing apparatus of the related art.
This data recording and reproducing apparatus is used as, for example, an AV server in a broadcasting station and the like, and it can record and reproduce data simultaneously. The data recording and reproducing apparatus has control signal input means 101, server control means 102, data accumulation means 103, file system management means 104, data input means 105 and data output means 106. The control signal input means 101 inputs an input control signal S1 for recording data and an output control signal S2 for reproducing data thereinto from outside in real time. The server control means 102 controls respective means in the apparatus based on the control signals S1 and S2 inputted into the control signal input means 101. The data accumulation means 103 is composed of semiconductor memories, hard disks or the like, and can record and reproduce data such as audio/visual data thereinto/therefrom. The file system management means 104 has management information (file system) for representing areas into which data have been recorded and areas (space areas) into which data can be recorded in areas of the data accumulation means 103, and it manages the areas for data recording in the data accumulation means 103 using the management information. The data input means 105 inputs data DIN, to be recorded in the data accumulation means 103, thereinto. The data output means 106 outputs data DOUT reproduced from the data accumulation means 103.
In the data recording and reproducing apparatus having such a constitution, when the server control means 102 receives an input control signal S1 which requests data recording from outside via the control signal input means 101, it reserves areas which are necessary for data recording in the data accumulation means 103 based on the management information owned by the file system management means 104, and thereafter records and accumulates inputted data DIN inputted via the data input means 105 into the data accumulation means 103. Moreover, when the server control means 102 receives an output control signal S2 which requests data reproduction from outside via the control signal input means 101, it reproduces data from areas into which the data have been recorded to be reproduced in the data accumulation means 103 based on the management information owned by the file system management means 104, and outputs the reproduced data DOUT via the data output means 106. The aforementioned data process according to the data recording and reproduction operations is performed per file unit.
The following will describe one example of the procedure for recording and reproducing plural data in a data recording and reproducing apparatus of the related art. Here, the following description will refer to the case where a file A whose data amount is 40 minutes and a file B whose data amount is 30 minutes are recorded in the data accumulation means 103 whose data recording capacity is 60 minutes. Moreover, the following will refer to the case where all the areas for data recording in the data accumulation means 103 are free, and the file A and the file B are recorded in this order into the data accumulation means 103 in the free state, and respective recorded data are reproduced one by one.
First, all the areas of 60 minutes for data recording in the data accumulation means 103 before data recording are in a data recordable state, namely, in the free state. In this state, when the file A is recorded, the recording areas occupied by the file A are 40 minutes, so the recordable free areas are 20 minutes. Therefore, at this time, the file B whose data amount is 30 minutes cannot be recorded. Next, after the file A is reproduced, all the reproduced file A is deleted from the areas. At this time, all the areas of the data accumulation means 103 of 60 minutes are in recordable free state. Next, when the file B is recorded, the recording areas occupied by the file B are 30 minutes, so the residual recordable areas are 30 minutes.
In the aforementioned data process, in case where the file B is desired to be recorded quickly just after the file A, it would be expected that the file B would be recordable at the point of time when the file A has been reproduced for 10 minutes, since originally recordable areas (completely space areas) of 20 minutes and the areas of the 10 minutes for which the file A has already been reproduced make areas for 30 minutes, which would allow enough space areas for recording the file B. Actually, however, in a data recording and reproducing apparatus of the related art, since the data recording and reproduction processes are performed completely per file unit, partial deletion of data, i.e., partial release of area, is not possible. Accordingly, the file B cannot be recorded unless the file A is wholly deleted.
As mentioned above, in the data recording and reproducing apparatus, when data are reproduced, for example, for broadcasting a program, since recording areas corresponding to portions where data have been already reproduced are not necessary, it is desired that the above areas would be released in order to enlarge recordable areas so that new material data may be recorded therein. In the related art, however, release of the area has been possible only by deleting data per file unit, so in this case, new data would become recordable only after reproduction of data included in one file is completed and the reproduced file is deleted. For this reason, even if plural data are tried to be recorded, there have been many cases where data cannot be recorded because recordable areas are less, thereby arising a problem that efficient data recording has been hindered.
Such a problem arises easily in the case where a relatively great amount of material data such as programs provided by a broadcasting station is processed in an AV server with a relatively small capacity composed of a semiconductor memory, for example.
The present invention has been achieved with such points of view. It therefore is an object of the present invention to provide a data recording and reproducing apparatus and method which can utilize areas for data recording efficiently.
A data recording and reproducing apparatus according to the present invention comprises:
recording and reproducing means for recording and reproducing data by using a non-linear accessible recording medium;
control means for controlling the recording and reproducing means so that data recorded in the recording medium are reproduced, and for outputting reproduction position information which represents a reproduction position of the data in the recording medium, and a release instruction for, while the data are being reproduced from the recording medium, releasing an area in the recording medium where the reproduced data have been recorded so that new data can be recorded in the area;
data management means for managing management information which represents the area in the recording medium where the data have been recorded and a recordable area where data can be recorded, through changing the management information, based on the release instruction and the reproduction position information outputted from the control means, so that new data can be recorded in the area corresponding to the release instruction; and
reproduction position transmission means for transmitting the reproduction position information outputted from the control means to the data management means.
In addition, a data recording and reproducing method according to the present invention is a method for recording and reproducing data by using a non-linear accessible recording medium, which includes:
the first step of reproducing data recorded in the recording medium and outputting reproduction position information which represents a reproduction position of data in the recording medium, and a release instruction for, while the data are being reproduced from the recording medium, releasing an area in the recording medium where the reproduced data have been recorded so that new data can be recorded in the area;
the second step of transmitting the reproduction position information outputted at the first step; and
the third step of managing management information which represents the area in the recording medium where the data have been recorded and a recordable area where data can be recorded, through changing the management information, based on the release instruction outputted at the first step and the reproduction position information transmitted at the second step, so that new data can be recorded in the area corresponding to the release instruction.
In addition, another data recording and reproducing apparatus according to the present invention comprises:
recording and reproducing means for recording and reproducing data using a non-linear accessible recording medium; and
control means for, while the data is being reproduced from the recording medium, inputting a release instruction for releasing an area in the recording medium where reproduced data have been recorded so that new data can be recorded in the area, and for controlling the recording and reproducing means through changing management information which represents the area in the recording medium where the data have been recorded and a recordable area where data can be recorded, based on the inputted release instruction, so that new data can be recorded in the area corresponding to the release instruction.
In addition, another data recording and reproducing method according to the present invention is a method for recording and reproducing data by using a non-linear accessible recording medium, which includes the steps of:
reproducing data recorded in the recording medium; and
inputting a release instruction for releasing an area in the recording medium where reproduced data have been recorded so that new data can be recorded in the area while the data are being reproduced from the recording medium, and controlling recording and reproduction through changing management information which represents the area in the recording medium where the data have been recorded and a recordable area where data can be recorded, based on the inputted release instruction, so that new data can be recorded in the area corresponding to the release instruction.
In another data recording and reproducing apparatus or method according to the present invention, when the release instruction is inputted for, while the data are being reproduced from the recording medium, releasing the area in the recording medium where the reproduced data have been recorded so that new data can be recorded in the area, the management information, which represents the area in the recording medium where data have been recorded and the area where data can be recorded, is changed based on the inputted release instruction, thereby controlling the recording and reproduction so that new data can be recorded in the area corresponding to the release instruction.
The above and further objects and features of the present invention will more fully be apparent from the following detailed description.